Fusing apparatus having an induction heated fuser roller

A fusing apparatus for heating and permanently fusing toner powder images onto an image carrying sheet;

• the fusing apparatus comprising;
• (a) a pressure roller;
• (b) a closed loop magnetic flux carrying member positioned adjacent said pressure roller and including a first side and a second side opposite said first side, said first side being located between said pressure roller and said second side;
• (c) an electrically conductive wire wound about said second side forming a primary transformer coil, said primary transformer coil having N1 number of turns and being connectable to an AC power supply source for inductively transferring AC electric energy to a secondary coil wound around said first side;
• and
• (d) a rotatable fuser roller forming a fusing nip with said pressure roller, said rotatable fuser roller having a rigid non-conductive core comprising a ceramic tube and a conductive metal sleeve that is shrink-fitted onto said ceramic tube for minimizing the thermal time constant of said rotatable fuser roll, said rotatable fuser roller being mounted around said first side of said closed loop magnetic flux carrying member and forming a secondary transformer coil inductively coupled to said primary transformer coil, and said conductive layer being inductively heated by power dissipated by current induced therein when said primary transformer coil is connected to said AC power supply source.